1. Field of the Invention
The present invention relates to a device for fastening a first part to a second part and particularly for fastening a lining element in the interior of a vehicle, which preferably is an airplane.
2. Description of the Background Art
From DE-A-199 00 267, DE-A-197 30 269, EP-A-1 215 082 and WO-A00/40436, a device for fastening a first part to a (stationary) second part of an aircraft is known, the first part being releasably connectable with the second part via a fastening element. The first part, for example, may be configured as a lining element with or without functional units such as, for example, an oxygen supply unit, reading lights, air nozzles or actuating elements for switching functional units on and off, such a lining element being adapted to be fastened to a C-shaped profile (second part). The fastening element comprises a basic body with a throughbore in which an actuating element coupled to a locking element is rotatably supported. The actuating element is, for example, a screw that can be turned by means of a screwdriver. The locking element having the shape of a parallelogram is disposed on that side of the basic body that faces the second part. Locking is effected by turning the locking element. To this end, the actuating element is axially pressed in an opposite direction to the biasing force of a spring in the direction of the second part, which means in the direction towards the C-shaped profile, which leads to the locking element being raised with respect to the abutting surface of the basic body abutting on the second part. Thus, the locking element is disengaged from abutting projections on the abutting surface of the basic body. Now, a turning of the locking element of about 90xc2x0 can be effected by turning the actuating element, so that the locking element is brought into a pre-locking position. In this pre-locking position, the locking element is secured, at the second part, against being taken along further when the actuating element is turned. The actuating element and the locking element are in threaded engagement so that a further turning of the actuating element leads to an axial relative movement of the actuating element and the locking element when the locking element assumes its pre-locking position. Thus, the locking element is moved towards the abutting surface of the basic body, whereby a press fit is achieved between the locking element, the basic body and the second part.
Due to the fact that the basic body of the fastening element obstructs the view to the locking element during assembly, the assembler cannot see the turning position of the locking element from the outside. On the basis of the rotational position of the actuating element that, as is explained above, is accessible by a screwdriver or similar tool and is visible from the lower surface of the basic body facing away from the abutting surface and that is configured in the manner of a screw head, the rotational position thereof is no indication as to which turning position the locking element assumes, either. Particularly, the assembler cannot see if the locking element presently assumes its pre-locking position or its final locking position. Moreover, in case of the known fastening elements, the assembler always has to make sure, via a tool, that the locking element assumes its pre-locking position in which the fastening element is held so as to be secured against detachment at the second part, even though not in a definitely fixed manner.
It is, therefore, an object of the present invention to provide a device for fastening a first part to a (stationary) second part of a vehicle, for example an aircraft, such that the mounting of the fastening element to the second part is simplified.
In order to solve this object, the invention provides a device for fastening a first part to a second part, particularly for fastening a lining element in the interior of a vehicle, preferably an aircraft, the device being provided with at least one fastening element connectable to the first part and releasably attachable to the second part. The at least one fastening element being provided with a locking element being supported at the fastening element so as to be movable between a disengaged position in which the fastening element is able to be set to the second part and to be detached therefrom, and a pre-locking position in which the fastening element is held at the second part, and an actuating element for moving the locking element between the disengaged position and the pre-locking position.
According to a further embodiment of the invention, the at least one fastening element is further provided with a first biasing element for biasing the locking element into the pre-locking position thereof, and a trigger element comprising at least one retaining projection for the locking element. The trigger element is supported at the fastening element between a retaining position, in which the at least one retaining projection retains the locking element in the disengaged position thereof, and a releasing position, in which the at least one retaining projection releases the locking element for moving into the pre-locking position. The trigger element is also being provided for abutting on the second part when the fastening element is set to the second part.
The fastening device according to the invention comprises at least one fastening element adapted to be connected to the first part, particularly in a pivotal manner, and to be releasably attached to the second part. At the fastening element, there is a locking element supported so as to be rotatable between a disengaged position and a pre-locking position. In the disengaged position, the fastening element can be attached to the second part or detached therefrom, whereas it is secured against unintentional detachment at the second part in the pre-locking position of the locking element.
Turning the locking element between its disengaged position and pre-locking position is effected by an actuating element rotatably supported on the fastening element. By this actuating element, the locking element can preferably be moved not only between the two afore-mentioned positions, but, moreover, into a final locking position as well in which the fastening element is retained at the second part in a definitely fixed manner (in a form-fitting and/or frictionally engaged manner). Therefore, it is suitable if the actuating element is configured as, for example, a screw, which includes at the end of its threaded shank facing away from the screw head, a stop forming a press fit for the locking element when it abuts on the stop. The clamping connection between locking element and stop effects that the locking element is taken along by the actuating element when the actuating element is turned. When the locking element is moved from the disengaged position into the pre-locking position, a further turning of the actuating element (screw) effects a release of the press fit and a tightening of the locking element against areas of the second part.
According to the invention, it is provided that the locking element is biased into its pre-locking position. This means that the locking element automatically moves into its pre-locking position if it is released upon assuming its disengaged position. The biasing spring can either engage directly on the locking element or be indirectly coupled thereto by engaging on the actuating element. Preferably, the biasing spring is configured as a torsion spring (spiral spring or helical spring) penetrated by the actuating element.
The turning movement of the locking element from the disengaged position into the pre-locking position is triggered by a trigger element abutting on the second part when the fastening element is attached thereto. Because of the abutment, the trigger element is transferred from a retaining position into a releasing position when the fastening element presses against the second part. In the retaining position, the trigger element blocks the movement of the locking element by at least one retaining projection, whereas the trigger element releases the locking element in its releasing position in which the at least one retaining projection is thus moved out of the path of movement of the locking element.
The advantage of the fastening device according to the invention is to be seen in that the locking element is in the disengaged position at that time when it is introduced into the second part and the fastening element, with pressure, abuts on the second part, in order to then automatically pivot into the pre-locking position. In the disengaged position, the locking element has no contact with the second part when the fastening element is introduced into it or abuts on it. For reasons of safety, the surfaces of the locking element and the second part, which contact each other in the state of attachment, are coated for protection against corrosion, for example. The advantage of the fastening device according to the invention is that this protective coating is not damaged by a contact of the locking element and the second part upon setting on the fastening device.
The locking element and the second part can be made of metal. Since the locking element is biased into its pre-locking position, a visually perceptible automatic contact occurs after the locking element has been introduced into the second part. Thus, the assembler receives an acoustic feedback when the locking element has assumed its pre-locking position.
In a further embodiment of the invention, the trigger element is biased into its retaining position by at least one biasing element. Thus, the trigger element safely assumes this retaining position which reduces the danger of the locking element making an unintended transition into the pre-locking position when handling the fastening element before the latter abuts the second part.
The afore-mentioned biasing element for the trigger element is suitably configured as a helical pressure spring. All other spring mechanisms or biasing means, however, are possible as well. This, by the way, also applies to the biasing element biasing the locking element into the pre-locking position thereof. Also, the movement of the locking element from the disengaged position into the pre-locking position does not necessarily have to be a turning movement. Other movements, for example lateral movements, are also possible.
Beside the automatic movement of the locking element into the pre-locking position, it is also suitable to additionally provide a visual indication as to whether the locking element has assumed its pre-locking position. Suitably, this is realized in that the locking element or the trigger element or the actuating element are coupled with an indicator element, preferably in the form of an indicator pin. This indicator element assumes different positions, depending on the assumption of the position of the locking element. Thus, for example, it would be conceivable that the indicator element projects from the fastening element when the locking element is in its pre-locking position. This has the advantage that the indicator element can be felt, which means that no direct visual contact with the indicator element is required to make sure that the locking element has assumed its pre-locking position.
The indicator element is connected to one of those elements of the fastening element that move in common with the locking element when the latter moves from the disengaged position into the pre-locking position. These elements are represented by the locking element in particular; alternatively, however, it might also be that the indicator element is coupled with the actuating element for the locking element. This requires that, which per se is the case, the actuating element moves in common with the locking element when the locking element is transferred from the disengaged position into the pre-locking position.
Alternatively, it is also possible to couple the indicator element with the trigger element. Namely, the locking element automatically moves into the pre-locking position when the trigger element assumes its releasing position.
As already explained above, the indicator element may be an element projecting from the fastening element in its one state and standing back with respect to the fastening element or being even with the outside thereof in its other state. It is also possible, however, that, when looking at the fastening element, the indicator element is visible in the one position and not in the other one. Those areas of the indicator element respectively visible may also have different colors. Finally, it is also possible to give a color to the indicator element which differs from that of the fastening element.
By providing the indicator element, a further visual and tactile indication possibility has thus been presented for the circumstance that the locking element is in its pre-locking position. These indication possibilities then exist in addition to the acoustic acknowledgment already mentioned above as to that the locking element has assumed its pre-locking position.
The above-described configuration of the fastening element according to the invention, with the feature that an indication is made as to whether the locking element has assumed its pre-locking position and final locking position, respectively, can be realized independent of whether the locking element is biased. Insofar, each modification by itself defines subject matter to be protected.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.